Molding sand milling machine



Dec. 15, 1942. H. L. BURG MOLDING SAND MILLING MACHINE 4 Shee ts-Sheet 1 Filed Dec. 4, 1940 grwe/WM Ham er L. flurg Dec. 15, 1942. 'BURG 2,304,882

MOLDING SAND MILLING MACHINE Filed Dec. 4, 1940 4 Sheets-Sheet 2 V H0merl.,Burg

Dec. 15, 1942. H. L. BURG MOLDING SAND MILLING MACHINE 4 sheets sheet' 3 Filed Dec. 4, 1940 ammo/whom Burg Homer L Dec. 15, 1942. H L Bu f 2,304,882

MOLDING SAND MILLING MACHINE Filed Dec. 4, 1940 Shams-Sheet 4 5/ 55 51 V '1 I 1 x & I I 4 W IWIIIIIINMIHIHIIHIWIIMWH N Hume/'1 fury H Wang. v

Patented Dec. 15, 1942 UNITED STATES ATENT OFFICE MOLDING SAND MILLING MACHINE Homer L. Burg, Dallas City, 111.

Application December 4, 1940, Serial No. 368,541

10 Claims. (Cl. 22--89) The present invention relates to molding sand milling machines.

The primary object of the invention is to provide a machine capable of operating upon molding sand to condition the same for re-use in molding operations by subjecting the same to a rotating brush having pliant bristles thereby causing the sand to be milled, cooled, cleaned, aerated and disintegrated in a short period of time.

A further object of the invention is to provide a machine of the above mentioned character capable of being moved over the floor of a foundry so that the molding sand, which is usually piled on the floor of the foundry may be operated on by a high speed rotary brush to cause metal particles and casting chippings to be removed from the sand and collected in a suitable receptacle associated with the machine and prepare the sand without carrying it to some stationary machine.

A still further object of the invention is to provide a machine of the above mentioned character capable of being moved over the floor of a foundry by mechanical propulsion means and steered by an attendant from the front end of the machine whereby said machine may be easily manipulated and brought into contact with the molding sand to be conditioned.

A still further object of the invention is to provide a leveling bar having fingers to act as a rake for the sand conditioning machine which will travel in advance of the rotary brush to level the sand on the floor and remove any castings or pieces too large to pass through the brush so that the brush will be presented to the sand over its entire longitudinal contacting area.

A still further object of the invention is to provide a machine of the above mentioned character having means for supplying additional sand which'may be dispensed in advance of the wire bristle rotary brush in order that the new sand or bonding material will be mixed with the used sand being conditioned.

A still further object of the invention is to provide a machine of the above mentioned character having a reservoir for supplying a jet of water in advance of the rotary brush whereby the sand being operated on may be wetted or tempered uniformly to proper moisture content A still further object of the invention is to provide a machine for conditioning molding sand by the action of a high speed rotary brush which is carried by the machine on the vertical median line thereof so that forward and backward tilt- 55 ing of the machine will not cause the high speed brush to contact the floor of the foundry or other surface upon which the machine is operated.

A still further object of the invention is to provide a machine for conditioning molding sand b means of a high speed rotary brush capable of being adjusted vertically so that the bristles of the brush will not contact the floor but will travel in close proximity thereto and may be adjusted as they become worn by abrasion in the sand milling operation.

Other objects and advantages of the invention will become apparent during the course of the following description, taken with the drawings, wherein,

Figure 1 is a side elevational view of the machine illustrating portions thereof broken away to show certain features in detail;

Figure 2 is a top plan view of the machine, illustrating the sections broken away to show the drive connection for the machine;

Figure 3 is a longitudinal cross-sectional view of the machine. illustrating the location of the rotary brush and showing the general arrangement of the supporting mechanism thereof;

Figure 4 is a fragmentary detail view of one of the drive connections, showing the means for moving the friction roller into and out of engagement with one or both of the supporting wheels;

Figure 5 is a detail plan view of the Water spray pipe for supplying a dampening medium to the sand prior to its conditioningf Figure 6 is a vertical cross-sectional view of Figure 4, further showing the eccentric support for one of the friction drive rollers;

Figure 7 is a vertical detail cross-sectional view of the sand feed hopper, illustrating the manner in which the dispensing openings are controlled;

Figure 8 is a side elevational view of the brush;

Figure 9 is a vertical cross-sectional view taken on line 9-9 of Figure 8, looking in the direction oithe arrows, illustrating in detail the construction of the brush; I

Figure 10 is a perspective view of one of the brush segments removed from the brush;

Figure 11 is a modified construction and is a side elevational view of a brush and conveyor for carrying out the invention;

Figure 12 is a vertical cross-sectional view taken on line l2l2 of Figure 11, looking in the direction of the arrows, further illustrating a modified form of the invention;

Figure 13 is a fragmentary longitudinal sec tional view showing a modification of the brush in which flexible elements, such as chains, are employed in lieu of the wire bristles, shown in Figures 1 to 12 inclusive; and

Figure 14 is a front elevational view of the scraper bar employed for leveling the sand and removing heavy particles therefrom by reason of the rake teeth carried by the scraper bar.

In the drawings, the reference character I!) will generally be employed to designate a rectangular wheeled frame comprising parallel side frame bars ll connected at the front by means of an angle bar l2 and at the rear by means of aconnecting bar l3. The frame bars H are pref? erably formed of channel irons or angle bars.

The wheeled frame is supported by drive wheels l4 mounted on a common axle l5 attached to the frame by a clamp l6 at each end so that the axle is stationary and the wheels l4 revolve thereon individually. The axle I5 is mounted intermediate the ends of the wheeled frame in order that the wheel frame will be supported at a point to properly balance the load it carries. Adjustably mounted in each of the flanges of the channel irons II is a pair of adjustable screw rods [1 slidably mounted in openings I8 formed in the channel irons so that each vertical rod I! may be adjusted by means of upper and lower adjusting nuts 19 and 20 respectively.

Carried 'by the upper end of the vertically adjusted screw rows I! is a platform 2! while the lower ends of each pair of adjustable rods I! are connected by longitudinal strips 22. The ends of the vertically adjustable rods [1 are provided with heads 23 which may be welded or otherwise rigidly attached to the vertically adjustable rods I! whereby said platform 2| and side strips 22 may move i unison when adjustment of the rods I1 is had.

Extending between the longitudinal side strips 22 is a rotary shaft'24 having its ends journalled in anti-friction bearings 25 bolted to the intermediate portion of the longitudinal side strips 22. Rigidly secured to the shaft 24 adjacent each end thereof, as shown in'Figures 3 and 8 to 10, are spaced hub collars 26 having spider arms or spokes 21 which support a cylinder 28. The hub collars are keyed to the shaft 24 by means of a key connection 29. Provided at the ends of the cylinder 28 are flange rings 30 which are adapted r to retain bristle carrying strips 3| having wire bristles 32, and 24 .6. ends Of said strips 3| are bevelled as at 31a. for being received under the bevelled edge 311a of the anchoring rings 30. The opposed flange rings 30 are held in place by @IlChOli g rods 33 having threaded on one end thereof nuts as at 3.4. Tightening of the nuts 34. draws the rings 36 together to securely hold .the bristle segments 3| tightly clamped to the.

cylinder 28 as is clearly shown in Fig. 9.

It is to be noted that the rotary brush is composed of a series of segments which are substantially key-stone-shaped in cross-section so that should the wire bristles 32 of one segment become damaged, this segment may be replaced by merely removing the anchoring rod 33 and substituting a new bristle section therefor.

Mounted on the platform 2! is an electric motor 35 having its armature shaft 36 extending transversely of the machine so that one end thereof may be provided with a pulley 31 over which is trained a belt 38 for driving a similar pulley 39 mounted on the rotary shaft 24 that carries the rotarywire brush. The pulley 31 is keyed to the shaft as at 40 as is also the pulley 39 as at 4|.

The opposite end of the armature shaft 36 is provided with a pulley 42 over which is trained a belt 43 for driving a pulley 44 mounted on a,

stub shaft 45 suitably supported in a bracket 46. The stub shaft 45 is provided with a gear wheel 41 which meshes with a gear wheel 48 mounted on a shaft 49 extending through and journalled in the side walls of a speed reduction gear box 50.

Mounted on the shaft 49 is a herringbone gear 5| which is adapted to mesh with a herring-bone gear 52 mounted on a driven shaft 53 also journalled in a gear box 50 and said gear 52 is considerably larger than the gear 5| so that rotation of the shaft 53 will be greatly reduced.

Transversely mounted on the front end of the machine is a rotary shaft 54 having its ends journalled in suitable bearing blocks 55 and on each end of the shaft 54 there is provided a friction drive roller 56 adapted to engage the inner periphery of the wheel rim l4 to impart rotation thereto. On one end of the rotary shaft 54, there is provided a sprocket wheel 5! adapted to be driven by a sprocket wheel 58 mounted on the shaft 53 by means of a chain 59 passing therearound so that operation of the motor 35 will cause a reduced speed to be imparted to the transverse rotary shaft 54.

Each of the bearings 55 supports the transverse shaft 54 by means'of interposed cam eccentric 59 which is operably mounted within the bearing 55 so that rotation of the eccentric 59 as by means of a connecting arm 60 will move the COII'GSPOIldr ing friction roller 56 or 51 into or out of engagement with the inner periphery of the right or left supporting wheels l4. In Figure 4, the bearing is specifically shown and is intended to represent the bearing for supporting and operating the wheel engaging friction roller 56 at the left side of the machine. It is to be understood, that the opposite bearing 55 is identical in construction and produces the same result.

Normally, both friction rollers 56 will engage the inner periphery of the wheel rims M to drive the same at a constant speed whereby the machine will be propelled forward in a straight line direction.

Each eccentric 59 is provided with anoperating lever 55 to which is attached a cable BI and said cables are passed over pulleys 52 ,rotatably carried by the frame structure ll so that the front ends of the cables 53 may be trained over the pulleys 54 and the free ends 55 attached to a lever 56 as at 57. The lower end of the lever 66 is bifurcated as at 63 and is adapted to straddle a transverse rock shaft 69, the ends of which are journalled in the side frame members 'H so that the shaft 59 may be rocked in both A pivot pin ii] is connected rotary directions. to the bifurcatedportion F58 of the shaft and extends through the rock shaft 59 so that the operating lever 66 may be rocked laterally on scraper bar II is provided at its'ends with sup- 'bar III'Ia to which is rigidly attached a series of porting links I4, one end of which is rigidly attached to a lug on the scraper bar as at while the opposite end is pivoted to a lug carried on the under side of each of the side frame bars I I and to the rear of the center of the rotary brush so that when raised, the scraper bar will swing free on the pivot as at 56. A coil spring 'iI has one end attached to the lug carried by the scraper bar as at 'I'Ia while the opposite end is anchored to a depending shield plate 78 as at T9. The'shield plates I8 are provided on each side of the frame and have their upper ends bolted as at 80 to the side channel frame members II. Attached to each end of the scraper bar H as at 83 is a cable 82 and said cables extend upwardly and are trained over pulleys 84 supported on brackets 85 secured to the channel shaped side members II. The cables 82 extend forwardly and have their ends as at 86 attached to the pulleys 87, mounted on each end of the rock shaft 69 so that rocking movement thereof will rotate the pulley drums 81 and elevate the scraper bar II from the floor surface.

Located between the front ends of the channel shapedside frame members II is a hopper 88 held in position by suitable supporting lugs 89 for containing fresh sand to be mixed with the sand being treated. The transverse rotary shaft 54 extends through the hopper and is provided with a rotary cylinder 90 for supporting a series of wire bristle segments 91 which carry wire bristles 92. The wire bristle sections 95 are held in position by longitudinal anchoring rods 93 similarly to the anchoring rods 33 of the rotary wire bristle brush 32.

It is to be noted that the wire bristles 9! engage a lower curved wall 94 of the hopper 88 and formed in the curved wall is a dispensing opening 85 adapted to be controlled by a sliding shutter 96, having an operating handle 9'! provided with a projection for engaging the rack teeth 98 so that the sliding shutter 96 may be held in an open position against the action of a coil spring 99 which has one end attached to the sliding shutter 98 while the opposite end is anchored to the hopper 88.

Secured to the forward portion of the downrake teeth I011) which are adapted to engage large particles such as foundry castings and remove them from the path of the rotary brush bristles 32. The bar Illla may be bolted or otherwise secured within the channel of the angle bar I01.

Mounted on the rear of the machine and between the side frame channel bars II is an inclined apron III) having the upper end, as at III, anchored in place as by means of welding wardly extending side plates I8 are outwardly converging sand guiding plates Illfl which project FIG that the sand will be directed under the rotary brush 32. Anchoring bolts Iill are provided for connecting the outwardly converging guide plates II!!! to the forward portion of the side plates 18. A brace bar N52 is mounted on each side of the frame and has its upper end as at I03 connected to the forward portion of the side channel frame members, while the opposite end is connected to a vertical bar I04 held in position along the forward marginal edge of the side plates I8 by means of screws or rivets I85. vThe lower end of each marginal supporting bar IE4 is formed with an angle portion IIMa to which is pivoted a foot portion I06 adapted to supportthe forward end of the machine and prevent the tilting thereof in a forward direction.

Extending between the downward depending side plates I8 is a scraper bar Id! which is angle shaped in cross-section and is provided with lugs ")8 at each end thereof for being held in place by machine screws or rivets I09. Car- -Iied within the channel of the bar I0! is a metal or the like while the lower end as at H2 is presented near the periphery of the wire brush 32. Side walls II3 are formed on the downwardly inclined skirt I I0 so that a fine wire mesh screen II4 may extend thereacross to screen the sand sprayed rearwardly by the rotary brush 3I. A wire screen pocket '5 is formed adjacent the upper end of the inclined skirt I I0 and comprises a continuation of the wire screen II4 held in place by the frame pieces HE. A rear wall II! is formed of screen and is held in position at its upper end by means of a cross bar II8. v

Downwardly extending from the upper end is a bafile screen II9 pivotally mounted between the side frame channel members II as at I20.

Means is provided for supplying water or a damping solution to the sand prior to its milling and includes a spray pipe I2I mounted between the side plates I8 and having a series of spray orifices I22 for directing a spray of water downwardly in advance of the rotary wire bristles 32. A supply pipe I23 is connected to the-spray pipe I2I and extends upwardly and rearwardly to a reservoir I24 mounted on the platform 22 I and held in place by means of supporting base members I25. A discharge spout I26 is formed on the lower portion of the reservoir I24 and is adapted to be connected with a supply pipe I23 by means of a hose section I2I whereby water will feed by gravity to the spray pipe I2I. A filler spout I30 is provided for replenishing the supply of liquid in the reservoir I24 when it is desired to spray the same in the aforesaid manner. i

Coil springs I3I are provided for normally urging the lever 60 in one direction so that the friction engaging rollers 56 will normally be held in driving contact relation with the inner periphery of the adjacent wheel rim I4.' A switch mounted on the forward end of the machine within easy reach of the operator may control the source of current to the motor 35 so that the operator may start and stop the machine at will.

In the form of invention described and as illustrated in Figures 1 to 10, there is disclosed a portable apparatus for the milling of sand in a foundry known in the trade as bench or floor molding wherein the machine is movable over a body of molding sand upon the floor of the foundry, with the rotary wire brush accomplishing the milling of the sand alone at the point of contact of the rotary wire brush with the pile of sand. It is to be understood that the screen II4 as shown in Figures 1 and 3 is not intended to accomplish the milling of the sand, as such milling takes place only at the point of contact of the wire brush with the sand, but has been provided merely for use as a separator i. e., to divide out the foreign matter in the molding sand and to allow only the milled sand to pass therethrough. As illustrated, the screen H4 is rigidly supported on the wheeled frame and is distinguishable from a vibrating riddle,

the rotary wire brush rotating with such speed that the completely milled sand is forcibly projected through the screen. Another method as used in foundries is what is known as system molding wherein mean is provided for moving the sand from a pile on the floor of the foundry to a molding sand miller and such an apparatus embodying a rotary'wire brush to accomplish the milling of the molded sand at the point where the sand is moved into a zone to be contacted by the rotary wire brush is shown in Figures 11 to 13.. In the modified form of the invention, shown in Figs. 11 and .12, a conveyor frame is provided at I [lb and includes a pair of uprights 1 lb, connected to inclined side framemembers 12b. The frame members lb and 12b ahe braced by suitable brace bars [3b and at the end by brace bars Mb having extensions l5b adapted to form bearings :for a transverse shaft Ifib having a suitable roller ,Hb over which is passed an endless conveyor belt or apron [8b for feeding granular material, such as sand or the like.

Extending between the uprights I lb is a rotary power driven shaft 19b on which is mounted a rotary brush 20b, The ends of the power shaft 19?) are journalled in suitable bearings Zlb, carried by the uprights 1 lb in order that the ends of the bristles of the brush 20b will be slightly spaced from the conveyor belt I8b. The brush 20b is constructed in identically the same manner' as the rotary'brush shown in Figs. 1 to 10 inclusive and since a detailed description thereof has already been given, it is believed unnecessary to further describe the same.

In the modified form of the invention, as disclosed in Figs. 11 and 12, sand is fed to the endless conveyor or apron belt .I8b so that the same will pass under the rotary brush b which is rotating in a clockwise direction so that the brush will mil-l, clean, blend and aerate the sand, the brush 2012 :being adjustable in position with respect to the conveyor belt |8b as the bristles of the brush become shortened by wear.

I have shown and described the entire machine to be operated by the electric motor '35 but it will be obvious that more than one motor may be employed if desired, such as having a separate motor to drive the ground wheels [4 and a separate motor for the brush 32 and this will permit bodily movement of the entire machine while the brush :32 is idle. I may provide means to hold the handle 60 against the action of the contact springs I31! thereby disengaging the friction rollers 56 when the machine is not running.

In the modified brush structure as shown in Fig. 13, the drum 280 is substantially identical to the drum shown in Figs. 1 to 10 inclusive, and said .drum is supported on .a shaft by means of spokes or arms 29c. Secured to the drum 280 at each end thereof are anchoring rings 390 having a bevelled inner wall 30d which are adapted to engage a, .strip 3Ic having bevelled ends 3ld which are adapted to be engaged by the bevelled portions 30d of the clamping rings .300 to securely hold the .strip .3lc to the drum 280.

A rod 330 extends through the clamping rings 30c and is threaded on one end for receiving a nut 34c whereby tightening of the nut will draw the clamping rings together and wedge the strip 3m in position around the periphery of the drum 28c.

Carried by the strip 3Ic is a series of flexible elements 350 comprising chain sections which ,may be anchored or otherwise fastened to the strip 3lc. If desired, flexible elements 350 could be formed of rope or similar material and the centrifugal action of the rotary drum 28 would be entirely depended upon to bring the flexible elements 350 into contact with the sand to produce the milling, cleaning, blending and aerating of the sand for the proper conditioning thereof.

It is to be understood that the form of the invention herewith shown and described -is to be taken as the preferred embodiment of the same and that various changes in the shape, size and arrangement of parts may be resorted to with-' out departing from the spirit and scope of the invention as claimed.

I claim: I

l. A portable machine for milling molding sand comprising a wheeled frame, a vertically adjustable platform mounted on the wheeled frame in the center thereof, a rotary pliant bristle brush suspended from beneath the platform for milling the sand in the zone of contact of the brush with the sand and a motor mounted on the platform for driving the wheeled frame and rotary brush, and means for vertically adjusting the platform and unitarily moving the motor and brush to retain relationship between the motor and brush.

2. A portable machine for milling molding sand comprising a two-wheeled frame, an adjustable platform carried by the wheeled frame a rotary pliant bristle brush suspended from beneath the platform for milling the sand in the.

zone of contact of the brush with the sand, a

motor mounted on the platform for driving the brush at a rapid rate of speed, a screen extend ing upwardly and rearwardly from the brush for collecting foreign particles in the sand, a hopper for fresh molding sand mounted on the forward portion of the frame a rotary wire milling brush in said hopper and a spray pipe for supplying liquid in advance of the brush on the platform wardly extending fingers carried by the wheeled 7 frame in advance of the brush, outwardly converging guide plates carried on the forward end of the frame for directing the sand inwardly toward the brush, means for supplying an additional charge of sand in advance of the brush and means for dampening the sand prior to its milling.

4. A machine for milling molding sand comprising e, two-wheeled frame, a platform vertically adjustable upon the frame, a rotary wire brush having closely associated radial flexible bristles disposed below the platform and vertically adjustable with the platform, a motor mounted on the platform, driving connections between the motor and brush and driving connections between the motor and wheeled frame for the propulsion of the latter, an inclined screen on the wheeled frame rearwardly of the brush for removing foreign matter from the sand, a floor scraper for directing the milled sand thrown by the brush onto the screen and means connecting the floor scraper to the driving connections between the motor and wheeled frame for elevating the floor scraper when the driving connections between the motor and wheeled frame are disconnected.

5. A machine for milling molding sand comprising a, two-wheeled frame, a platform vertically adjustable upon the frame, a rotary wire brush having closely associated radial flexible bristles disposed below the platform and Vertically adjustable with the platform, a motor mounted on the platform, driving connections between. the motor and brush and driving connections between the motor and wheeled frame for the propulsion of the latter, an inclined screen on the wheeled frame rearwardly of the brush for removing foreign matter from the sand, and an inverted substantially U-shaped guard frame overlying the inclined screen and positioned rearwardly of said rotary wire brush for directing the thrown milled sand onto said screen.

6. A machine for milling molding sand comprising a two-wheeled frame, a platform vertically adjustable upon the frame, a rotary wire brush having closely associated radial flexible bristles disposed below the platform and vertically adjustable with the platform, a motor mounted on the platform, driving connections between the motor and brush and driving connections between the motor and wheeled frame for the propulsion of the latter, an inclined screen on the wheeled frame rearwardly of the brush for removing foreign matter from the sand, an inverted substantially U-shaped guard frame overlying the inclined screen and positioned rearwardly of said rotary wire brush for directing the thrown milled sand onto said screen, a screened collection receptacle for foreign matter at the upper end of said inclined screen and a hinged baflle in said screened receptacle.

7. In a portable machine for milling molding sand, a frame comprising side bars, an axle journalled at its ends in the side bars, a ground wheel on each end of the axle, Vertically adjustable elements carried by the side bars and extending above and below the same, a platform secured to the upper ends of said adjustable elements, a rotary wire brush having closely associated radial flexible bristles rotatably supported by the lower ends of said elements, and a motor on said platform having a drive connection with the brush, the vertical adjustment of said elements controlling the normal position of the brush relative to the sand row while maintaining the normal drive relation between the motor and brush.

8. In a portable machine for milling molding sand, a two-wheeled frame, a platform above the wheeled frame, a rotary wire brush having closely associated flexible bristles below the frame, vertically adjustable means on the frame for the support of the platform and brush and maintaining constant relationship therebetween, a motor mounted on the platform and selective drive connections between the motor, rotary brush and wheeled frame for driving the rotary brush at a rapid speed and for propelling and steering the wheeled frame.

9. In a portable machine for milling molding sand, a two-wheeled frame, a platform above the wheeled frame, a rotary wire brush having closely associated flexible bristles below the frame, vertically adjustable means on the frame for the support of the platform and brush and maintaining constant relationship therebetween, a motor mounted on the platform and a selective drive connections between the motor, rotary brush and wheeled frame for driving the rotary brush at a rapid speed and for propelling and steering the wheeled frame, the drive connection between the motor and wheeled frame including disks frictionally engaged with the rims of the frame wheels and means for controlling engagement of the disks with the wheel rims whereby the machine may be forwardly propelled and steered.

10. A portable machine for milling molding sand comprising a two-wheeled frame, a, vertically adjustable support mounted on the wheeled frame within the extreme diametric dimensions of the wheels, a rotary wire brush cylindrical in end elevation and having closely associated radial flexible bristles forming a bristle mass uninterrupted over the entire peripheral surface thereof mounted on the support, a motor on the support for driving the wheeled frame and rotary brush, and means for vertically adjusting the support with the brush and motor Without disturbing the relationship between the brush and motor.

HOMER L. BURG. 

